This invention relates to an apparatus for measuring the quantity of a liquid or gas flow, especially a low-boiling liquid gas, through liquid outlet means of a storage tank provided with liquid inlet and outlet means.
A method for measuring the quantity of flow of a liquid is known wherein a baffle is disposed in the current flow, whereby there is a pressure drop in the flow of the liquid past the baffle and this pressure drop can be measured by conventional means. The pressure drop, along with the known throughflow rate of the baffle, can be utilized with the aid of Bernoulli's theorem and the continuity relation for calculating the fluid quantity.
A disadvantage of this method is the inaccurate measurement of smaller quantities of fluid flows. Furthermore, in measuring the quantity of fluid flow of a low-boiling liquid gas which is near its boiling point, increased evaporation losses occur due to the pressure drop in the baffle, having a disadvantageous effect on the result of the measurement.